Since the United States Government made the NAVSTAR satellite constellation's timing signals available for civilian use in the 1980s, location-based services have become increasingly popular. Many automobile manufacturers now offer global positioning satellite (GPS)-based locator devices as an option. These units are typically integrated into the vehicles' dashboard console. Also, other companies make aftermarket GPS devices for mounting in automobiles, boats and other vehicles, and even hand held devices for hiking, exploring or other recreational uses. Such GPS devices offer relatively high accuracy and universal availability and thus provide an acceptable solution for relatively inexpensive, precise positioning.
In order to meet FCC enhanced 911 (E911) requirements and to provide consumers with a mechanism for accessing location information using an appliance they already, own, commercial mobile radio service providers (CMRSPs) have prompted their device manufacturers to integrate GPS receivers into phones, PDAs and other communication appliances supported by their networks. As a result, users are able to view map and location information directly on their phones, PDAs, etc.. The capability and accuracy of the devices are constrained by native memory of the device. Also, the data used by the devices is static and therefore becomes outdated quickly.